Electrical rectifier construction



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ELECTMCAL mecum-1ER CONSTRUCTION Filed May '7, 1947 j@ `177 Mij! 141i MZ 14 i-, 5M w n In lzsalmon.,

Patented May 30, 1950 ELECTRICAL RECTIFIER CONSTRUCTION Linnie K. Bedding, Wllkinsburg, and Conrad H. Zier-dt, Rosedale, Pa., assignors to The Union Switch and Signal Com Dany, Swissvale, Pa., a

corporation of Pennsylvania Application May 7, 1947, Serial No. 746,544

8 Claims. (Cl. 175-366) r Our invention relates to electrical rectiers ln.

which each rectifying element comprises a disc composed of a metal or metalloid having a layer or layers of suitable material such as a compound of the metal or metalloid deposited or otherwise formed thereon.

More particularly our invention relates to a rectier construction in which the disc or plate of each rectifying element is provided on both faces with a layer of compound or other applied material and which layers have a. conducting coating applied to or formed upon their outer surfaces. The disc or plate and the outer conducting coatings of each rectifying element as such constitute its electrodes.

The invention has for its object to provide a novel and improved arrangement for electrically interconnecting the above referred to outer conducting coatings of the rectifying element which arrangement does not involve the use of special tools or complicated parts. and which readily lends itself to assembly of individual elements and associated contacting parts in face-to-face stacked relationship on an insulated supporting rod.

According to the principal feature of our invention the outer conducting coatings on opposite sides of the plate or disc are electrically connected together by a spring washer or other conducting spring contact member which extends through an aperture in the plate or disc but is insulated from the plate or disc and which is clamped between two contact washers disposed one on each side of the plate or disc in electrical engagement with the coatings.

The invention is illustrated by way of example in the accompanying drawings in which Fig. i is a longitudinal sectional view of a rectiiier constructed in accordance with one form of our invention. Fig. 2 is a side view of one of the rectifying elements shown in Fig. 1, a portion of the element being broken away or removed to better show the construction. Fig. 3 is a view in side elevation of one of the contact washers 9 shown in Fig. 1. Fig. 4 is a view-in side elevation of one of the insulating rings 8 shown in Fig. 1. Fig. 5 is a view in side elevation of one of the spring contact washers I shown in 1. Fig. 6 is a view in transverse section of a portion of a. rectiner embodying the invention in which an alternate form of rectifying element is employed.

Similar reference characters refer to similar parts in each of the several views.

Referring now to the drawings. the rectifier 2 stack illustrated comprises two asymmetric elements each consisting of a plate I of copper provided on both faces with a layer 2 of copper oxide, the outer surface of which is coated with a conducting contact layer 3. Each plate I is provided with a central hole 4 through which a rod 5 surrounded by an insulating sleeve 6 passes with considerable clearance. Each copper plate l with its associated oxide layers 2 constitutes a unit rectifyin'g element of Well-known construction.

The diameter of the hole 4 in each plate I is suiciently large to permit a metal spring washer l surrounded by an insulating ring 8 to be interposed between the inner edge of the plate and the sleeve 6. Each spring Washer 'l is of conducting material and is of such dimensions that it will make good electrical contact with both of two adjacent metal contact washers 9 clamped in intimate electrical contact with the contact layers 3 on opposite sides of the plate I. It should be particularly pointed out that while the spring washer 1 is of the common formillustrated, such part might be replaced by any one of a number of springs,discs or washers so constructed that they will make positive electrical contact with the contact washers 9 in the above stated manner. The insulating ring 8 is sufficiently smaller in width than the spring washer 'I in the compressed state to insure clearance with the adjacent sides of contact washers 9 and yet provide for insulating the washer l from the copper plate I.

The metal contact washers 9 are of rigid conducting material, preferably steel, and are each provided with a central hole I0 through which the insulating sleeve 6 passes. Each washer 9 makes contact on one side with the metal contact layer 3 of the adjacent plate I over an annular central area, and has a portion of said one side surrounding the hole IU counterbored or otherwise recessed, such recessed portion extending radially outward from hole I0 to a point beyond the inner edge of the layer 3.

It is apparent from the above that when the two metal contact washers 9 are clamped in intimate engagement with opposite sides of a rectifying element in the manner just described and also in intimate engagement with opposite sides of spring washer 1. the two contact layers 3 are electrically interconnected by means of the assoclated spring washer and the contact washers, and either of the contact washers constitutes the negative terminal of a unit rectier.

In the arrangement as shown, connection to the copper plate or positive electrode I of each rectifying element is eilected by means of a sheet metal connector II soldered or otherwise secured to a lug Il formed integrally with the copper plate I. Each connector II' is provided with a central hole I2 by which it is mounted on the insulating sleeve Bland ls insulated from an adjacent contact washer 9 by an insulating spacer I3. Connector II thus constitutes the positive terminal for the associated rectifier element.

Fig. 1 of the drawings illustrates one method of assembling two rectier elements provided with contact means embodying our invention into a stack in such manner that the elements are connected in series. It will be noted that as here shown one of the contact washers or negative terminals 9 associated with the one element is in face-to-face electrical contact with the sheet metal connector or positive terminal I I associated with the other element. At each end of the rectifier stack, as shown, standard metal contact spacers I5 establish electrical contact between the positive or negative, as the case may be, terminal of the outermost rectifying element and an end terminal connector I6, similar to the connector II, to which connector I6 connection is made to external circuit wires I1. On the outer side of the end terminal connectors I6 an insulating end plate I8 similar in shape to but of somewhat greater dimensions than plate 'I` is interposed between the connector I6 and a reinforced insulating end washer I9, the whole stack assembly of rectifyingelements with associated contacting parts, spacers, end plates and end washers being clamped together on the insulated rod V5 by means of nuts 2i) at each screw-threaded end of the rod, cupped spring washers 2i being interposed between the nuts 20 and the end washers I9 so as to enable any desired degree of resilient compression to be effected while permitting any expansion occurring during the operation of the rectier.

It should be clearly understood that our invention is not limited to the particular form and arrangement of the parts above described and illustrated by way of example, nor is it limited to use with rectier elements of the copper oxide type. For example, in Fig. 6 we have shown it applied to a selenium rectier element consisting of a metal carrier plate 22 provided on each side with a selenium layer 23 the outer surface of which is in contact with a metallic counterelectrode 24. The two counterelectrodes 24 as here shown are connected together by means embodying our invention in the same manner that the contact layers 3 of each asymmetric element in Fig. 1 are connected together.

One advantage of a rectiiler construction embodying our invention is that the parts which are provided for making contact with the outer faces of the rectifier elements are simple and reliable and can readily be assembled into a stack without the use of special tools.

Another advantage of a rectifier construction embodying our invention is that the parts employed are of rigid construction and provide good electrical contact with the faces of the rectifying elements over relatively wide areas spaced from the edges of the faces. The wide contact areas provided permit rapid heat transfer away from the elements and insure eiective cooling.

Although we have herein shown and described only one form of electrical rectiiler construction embodying our invention, it is to be understood that various changes and modifications may be clamped against each conducting layer of said element. and spring contact means clamped between said washers in said aperture but insulated from said metallic plate.

2. In combination, an asymmetric element made up of an apertured metallic plate provided on each side with a conducting layer separated from the plate by a layer of material for producing a rectifying junction, contact washers clamped against eaclil conducting layer of said element, and means for electrically connecting said contact washers comprising a spring member disposed in said aperture between said' contact washers, said spring member being in electrical engagement with said washers but insulated from said metallic plate.

3. In combination. an asymmetric element made up of an apertured metallic plate provided on each side with a conducting contact layer separated from the plate by a layer of material for producing a rectifying Junction, two contact washers of conducting material one clamped against each of said contact layers and each provided on the side adjacent the associated contact layer with a central recess which extends outwardly to a point beyond the inner edge of the contact layer. and' a spring contact member extending through the aperture of but insulated from said plate and making electrical contact with the recessed faces of said two contact washers.

4. A rectifier unit' comprising an asymmetric element made up of an apertured metallic plate provided on each side with a conducting contact layer separated from the plate by a layer of material for producing a rectifying junction, two conducting contact washers one disposed adjacent eachside of said element in electrical engagement with the associated contact layer and each provided with an aperture of smaller diameter than the aperture of said plate, an apertured spring contact member extending through the aperture of said plate and making electrical contact with both of said washers but which spring member is insulated from the plate. an insulated rod extending through the apertures in said plate, said contact washers and said spring member, and means provided on said rod for clamping said element, said washers and said spring member together, said unit constituting a half wave rectiiler of which said plate serves as one terminal and said contact washers jointly serve as the other terminal.

5. A rectiiler unit comprising an asymmetric element made up of an apertured metallic plate provided on each side with a conducting contact layer separated from the plate by a layer of material for producing a rectifying junction, two conducting contact washers one disposed adiacent each side of said element in electrical engagement with the associated contact layer and each provided with an aperture of smaller diameter than the aperture of said plate, an apertured spring contact member extending through the aperture of said plate and making electrical contact with both of said washers but which spring member is insulated from the plate, a connector provided with an aperture, said connector being connected to said plate and disposed adjacent to but insulated from one of said contact washers, an insulated rod extending through the apertures in said plate, said contact Washers, said spring member and said connector, and means provided on said rod for clamping said element, said washers, said spring member and said connector together. said unit constituting a half wave rectifier of which said connector serves as one terminal and said contact washers jointly serve as the other terminal.

6. A rectifier unit comprising an asymmetric element made up of an apertured metallic plate provided on each side with a conducting contact layer separated from the plate by a layer of material for producing a rectifying junction, two contact washers of conducting material each provided with an aperture of smaller diameter than the aperture of said plate and one clamped against each of said contact layers but spaced from the edges thereof by reason of an annular central recess in the washer which extends radially outward from the aperture to a point beyond the inner edge of the contact layer and by reason of the outer edge of the washer lying wholly within the outer edge of the contact layer, a conductive connector provided with an aperture of similarsize to the apertures of said washers the apertured end of which is adjacent the outer face of but insulated from one of said contact washers and the other end of which is connected to said plate on its outer perimeter, a rod surrounded by an insulating sleeve extending through the apertures in said plate, said contact washers and said connector and provided with means for clamping said plate, said contact washers and said connector together, and a.

spring contact member supported on said insulated rod and extending through the aperture of but insulated from said plate, said spring contact member being compressed between the recessed faces of said two contact washers in intimate electrical engagement therewith, said unit constituting a half Wave rectiiier of which said connector constitutes one terminal and said contact washers together constitute the other terminal.

7. An asymmetric unit including an asymmetric element comprisingan apertured metallic plate and at least one layer of material on each surface of the plate to provide similarly asymmetric electrical conductive properties between both sidesof the element and the plate itself; a pair of contact washers, one on each side of the asymmetric element; spring contact means extending through the ifaperture; and means clamping the washers and the element together in a stack so that the washers engage and compress the spring contact means to form an electrical connection between the opposite sides ofthe element, said plate serving as one terminal of the asymmetric unit and said washers jointly serving as the other terminal.

8. An asymmetric unit including an asymmetric element comprising a metallic plate and at least one layer of material on each. surface of the plate to provide similarly asymmetric electrical conductive properties between both sides of the element and the plate itself; a pair of contact washers, one on each side of the asymmetric element, each washer having a recess facing said element; spring contact means insulated from said plate and having its ends received. in said recesses; means clamping the washers and the element together in a stack so that the washers engage and compress the spring contact means to form an electrical connection between the opposite sides of the element; one terminal for the asymmetric unit electrically connected to the plate; and a second terminal for the asymmetric unit electrically connected to one of the Washers.

LINNIE K. HEDDING. CONRAD H. ZIERDT.

REFERENCES A CITED FOREIGN PATENTS Number Country Date Australia Deo. 2, 1941 

